A human computable password management scheme is given by a
human computable function f. A human computable function should be easy for a human
to evaluate in his head (e.g., without pen/paper/calculators). To create his
passwords the user first memorizes a secret mapping (e.g., a mapping from characters to digits, or
a mapping from pictures to digits). To generate a password we first select a
series of random public challenges. The user responds to a public challenge by
evaluating f on inputs specified by the secret mapping and the public challenge C.The user generates his passwords by computing
the response to the series of public challenges.

For each challenge the examples.txt file is a set of single
digit challenge response pairs. Given and the single-digit challenge the
challenge response pair would be written in the following format: .
The secret mapping for each challenge was chosen uniformly at
random.

The password challenges file is a set of 10-digit password challenges
where each single digit challenge is written in the following format: {1,2, ,k}.
The challenges form the ith 10-Digit Password Challenge. The
goal of the human computable password challenge is to guess the ith password for some value .